The method that works for me is to first tighten everything up, fill the m/c with fluid, open the banjo bolt on the caliper until a stream of fluid appears and then tighten it. Then, with the top of the m/c open, I give the brake lever small squeezes which will allow air that is still in the line to bubble up through the fluid return hole (the smaller of the two holes) in the m/c. Once the bubbles stop appearing, refill the m/c to the proper level and begin bleeding by opening the bleeder bolt while squeezing the brake lever fully. Re-tighten the bleeder hole before releasing the brake lever. This step will possibly need to repeated a dozen or more times, but by the fourth or fifth time you should see fluid begin to flow through the bleeder, and just squeezing the lever should begin to give you some resistance and therefore braking action.
I did find that even with cleaning and rebuilding my original m/c I still could not make it work, so I bought an aftermarket m/c from USAMotorcycles on the 'bay. Also, if you don't see the small bubbles while doing the small squeezes it is very possible that the return hole is plugged and will need to be opened. To do that I ground a .018" guitar string down to almost a pinpoint on my my grinder. It is a TINY hole.
HTH.